Debulking catheters and methods

ABSTRACT

A method of removing material from a blood flow lumen includes providing a device having a cutting element and an opening, the cutting element being movable relative to the opening. The method then includes advancing the device through a patient&#39;s vascular system to the blood flow lumen. Finally, the method involves moving the cutting element and the opening relative to the blood flow lumen so that a continuous piece of material is severed by the cutting element and directed into the opening as the cutting element and opening move through the blood flow lumen, the continuous piece of severed material being directed into the device for removal from the patient. The method may include providing a device having a rotatable cutter that, in some embodiments, is not parallel to the longitudinal axis of the device, is movable, has retracted and deployed positions, or any combination thereof. The method may further include forcing the opening toward the wall of the vascular site after the advancing step and before the moving step.

CROSS-REFERENCES TO RELATED APPLICATIONS

The present application is a continuation of U.S. patent applicationSer. No. 11/012,876, filed Dec. 14, 2004, which is acontinuation-in-part of U.S. patent application Ser. No. 10/288,582,filed Nov. 4, 2002, now abandoned, entitled “Debulking Catheters andMethods” which claims the benefit of Provisional Application No.60/381,632, filed on May 17, 2002, entitled “Debulking Catheter” andwhich is also a continuation-in-part of U.S. patent application Ser. No.10/027,418, filed Dec. 19, 2001, entitled “Debulking Catheter”, whichclaims the benefit of Provisional Patent Application Ser. No.60/257,704, filed Dec. 20, 2000, entitled “Debulking Catheter” andProvisional Patent Application Ser. No. 60/272,273, filed Feb. 27, 2001,entitled “Debulking Catheter”, the complete disclosures of which areincorporated herein by reference.

The present application is also related to U.S. patent application Ser.No. 09/377,884, filed Aug. 19, 1999, entitled “Apparatus and Methods forMaterial Capture and Removal” and Ser. No. 09/377,894, filed Aug. 19,1999, entitled “Apparatus and Methods for Removing Material From a BodyLumen,” the complete disclosures of which are incorporated by reference.

BACKGROUND OF THE INVENTION

The present invention relates generally to systems and methods fordebulking body lumens. More particularly, the present invention relatesto atherectomy catheters for excising atheroma and other materials fromblood vessels and from stents.

Cardiovascular disease frequently arises from the accumulation ofatheromatous material on the inner walls of vascular lumens,particularly arterial lumens of the coronary and other vasculature,resulting in a condition known as atherosclerosis. Atherosclerosisoccurs naturally as a result of aging, but may also be aggravated byfactors such as diet, hypertension, heredity, vascular injury, and thelike. Atheromatous and other vascular deposits restrict blood flow andcan cause ischemia which, in acute cases, can result in myocardialinfarction. Atheromatous deposits can have widely varying properties,with some deposits being relatively soft and others being fibrous and/orcalcified. In the latter case, the deposits are frequently referred toas plaque.

One conventional treatment for cardiovascular disease is the use ofstents. Endoluminal stents are commonly used to treat obstructed orweakened body lumens, such as blood vessels and other vascular lumens.Once deployed in the blood vessel, the stent can remain in the bodylumen where it will maintain the patency of the lumen and/or support thewalls of the lumen which surround it. One factor impeding the success ofstent technology in endoluminal treatments is the frequent occurrence ofin-stent restenosis, characterized by proliferation and migration ofsmooth muscle cells within and/or adjacent to the implanted stent,causing reclosure or blockage of the body lumen.

Atherosclerosis and restenosis can be treated in a variety of ways,including drugs, bypass surgery, and a variety of catheter-basedapproaches which rely on intravascular debulking or removal of theatheromatous or other material occluding a blood vessel. Of particularinterest to the present invention, a variety of methods for cutting ordislodging material and removing such material from the blood vesselhave been proposed, generally being referred to as atherectomyprocedures. Atherectomy catheters intended to excise material from theblood vessel lumen generally employ a rotatable and/or axiallytranslatable cutting blade which can be advanced into or past theocclusive material in order to cut and separate such material from theblood vessel lumen. In particular, side-cutting atherectomy cathetersgenerally employ a housing having an aperture on one side, a blade whichis rotated or translated by the aperture, and a balloon to urge theaperture against the material to be removed.

Although atherectomy catheters have proven very successful in treatingmany types of atherosclerosis and in-stent restenosis, improvedatherectomy catheters and methods are continuously being pursued. Forexample, many currently available side-cutting atherectomy cathetershave difficulty in capturing occluding material in the cutting aperture.To facilitate material capture, the cutting aperture is frequentlyelongated to increase the area into which the material can penetrate.Such elongation typically requires an equivalent lengthening of thecutter housing. Since most cutter housings are rigid, such lengtheningmakes it more difficult to introduce the distal end of the catheterthrough tortuous regions of the vasculature.

Another shortcoming of many currently available atherectomy catheters isthat they typically require a balloon positioned opposite the cuttingwindow to urge the cutting window into contact with occluding material.Such balloons, however, unduly increase the size of the distal portionof the catheter. Even with the balloon, the amount of material that canbe removed by conventional atherectomy catheters is limited by the sizeof the cutting window. Other disadvantages of some catheters includecutting elements with less than ideal hardness, inadequate storage spacewithin the catheter for containing removed material, sub-optimal guidewire lumens, and/or the like.

For these reasons, it would be advantageous to have atherectomycatheters, and methods for their use, which could access small, tortuousregions of the vasculature and remove atheromatous and other occludingmaterials from within blood vessels and stents in a controlled fashion.In particular, it would be desirable to have atherectomy catheters andmethods which could facilitate capturing and invagination ofatheromatous materials. Ideally, such catheters and methods would beadaptable for use in a variety of body lumens, including but not limitedto coronary and other arteries. At least some of these objectives willbe met by the present invention.

The present invention also relates to methods and devices for removingtissue from a body lumen such as a blood vessel or other vascularlocation. In particular, the present invention may be used for removingmaterial from a vascular location but may find uses in other body lumensas well. It is understood that although the invention may be describedwith respect to use in blood vessels the methods and devices of thepresent invention may be practiced in any body lumen.

The present invention also relates to methods and devices for removingtissue from an atherectomy device and for storing material which hasbeen removed from the atherectomy device.

BRIEF SUMMARY OF THE INVENTION

The present invention provides catheters and methods for removingmaterial from (or “debulking”) a body lumen. Catheters of the presentinvention may be used in a variety of body lumens, including but notlimited to intravascular lumens such as coronary arteries. Typically,debulking catheters are used to remove occlusive material, such asatherosclerotic plaque, from vascular lumens, but they may alternativelybe used to remove other materials. Generally, debulking cathetersinclude a proximal portion, a distal portion having an opening (or“window”), and a cutting element (or “tissue debulking assembly”) whichmay be exposed through the opening to contact material in a body lumen.The catheter debulks a body lumen when it is moved while the cuttingelement is in contact with the material in the lumen.

In one aspect of the present invention, a method of removing materialfrom a blood flow lumen includes: providing a device having a cuttingelement and an opening, the cutting element being movable relative tothe opening; advancing the device through a patient's vascular system tothe blood flow lumen; and moving the cutting element and the openingrelative to the blood flow lumen so that a continuous piece of materialis severed by the cutting element and directed into the opening as thecutting element and opening move through the blood flow lumen, thecontinuous piece of severed material being directed into the device forremoval from the patient. In some embodiments, the providing step iscarried out with the cutting element being movable between a deployedposition and a retracted position, the cutting element extending out ofthe opening when in the deployed position and not extending out of theopening when in the retracted position. In such embodiments, theadvancing step is typically carried out with the cutting element beingin the retracted position, and the moving step is typically carried outwith the cutting element being in the deployed position.

In some embodiments, the providing step is carried out with the cuttingelement extending beyond the opening a distance of about 0.025 mm toabout 0.64 mm. In other embodiments, the providing step is carried outwith the cutting element being rotatable, and with the moving step beingcarried out with the cutting element rotating when severing thematerial. In some embodiments, for examples, the providing step iscarried out with the device having a longitudinal axis, and the movingstep is carried out with the cutting element rotating around an axiswhich is not parallel to the longitudinal axis of the device. In otherembodiments, the providing step is carried out with an axis around whichthe cutting element rotates being movable relative to the opening.

In some embodiments, the moving step is carried out by moving thecutting element and window in a distal direction. Optionally, in suchembodiments the moving step may be carried out with the material beingcontained in the device at a location distal to the cutting element.

Other embodiments may further include the step of forcing the openingtoward the wall of the vascular site after the advancing step and beforethe moving step. In such embodiments, the forcing step may be carriedout by bending the device so that the opening is forced against the wallof the vascular site. Optionally, the providing step may be carried outwith the opening being on a side of the device, the forcing step may becarried out to force the side against the blood flow lumen, and themoving step may be carried out with the cutting element extending out ofthe opening, the cutting element directing the continuous piece ofmaterial into the opening.

The present invention is also directed to an atherectomy device whichhas a second opening in the body which is selectively closed or openedby a user. The second opening is closed when the cutting element is usedto cut material from the vascular location and is opened when removingmaterial from the containment chamber. The guidewire may be used to keepthe second opening closed while the guidewire is positioned in theguidewire lumen. The material may be forced through either the secondopening or the first or working opening through which the materialenters the device. The material may be forced through one of theopenings using any suitable medium or device such as a fluid, a pusherelement or the cutting element.

In another aspect of the present invention, the device may include twoor more detachable containment chambers. By providing more than onedetachable containment chamber the user may replace one of the chamberswhile the other chamber is being cleaned.

For a further understanding of the nature and advantages of theinvention, reference should be made to the following description takenin conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a debulking catheter of the presentinvention;

FIG. 1A is a side view of a portion of a debulking catheter as in FIG.1, where the body has a rigid distal portion with a bend, according toone embodiment of the present invention;

FIG. 2 is an exploded view of an exemplary distal portion of thedebulking catheter of the present invention;

FIG. 3A is an end view of the distal portion of the debulking catheterof FIG. 1 in which the cutter is in a closed position in the catheterbody;

FIG. 3B is a sectional view along Line A-A of FIG. 3A; FIGS. 3C and 3Dare views of the distal portion of a debulking catheter, where thedistal portion has a locking shuttle mechanism;

FIG. 4A is an end view of the distal portion of the debulking catheterof FIG. 1 in which the cutter is in an open position outside of thecutting window;

FIG. 4B is a sectional view along Line A-A of FIG. 4A; FIGS. 4C and 4Dare views of the distal portion of a debulking catheter, where thedistal portion has a locking shuttle mechanism;

FIG. 5A is an end view of the distal portion of the debulking catheterof FIG. 1 in which the cutter is in a packing position within a tip ofthe catheter;

FIG. 5B is a sectional view along Line A-A of FIG. 5A;

FIGS. 6 to 8 illustrate a monorail delivery system of the presentinvention;

FIG. 9A is a perspective view of a cutter of the present invention;

FIG. 9B is an end view of the cutter of FIG. 9A;

FIG. 9C is a sectional view of the cutter along Line A-A of the cutterof FIGS. 9A and 9B;

FIG. 10A is a perspective view of an in-stent restenosis cutter of thepresent invention;

FIG. 10B is an end view of the cutter of FIG. 10A;

FIG. 10C is a sectional view of the cutter along Line B-B of the cutterof FIGS. 10A and 10B;

FIG. 11A is a perspective view of another in-stent restenosis cutter ofthe present invention;

FIG. 11B is an end view of the cutter of FIG. 11A;

FIG. 11C is a sectional view of the cutter along Line C-C of the cutterof FIGS. 11A and 11B;

FIG. 11D is a side view of another embodiment of a cutter, shownpartially within a catheter body;

FIG. 12 illustrates a proximal handle and cutter driver of the presentinvention;

FIG. 13 illustrates a cutter driver with a handle cover removed;

FIGS. 14 to 16 illustrate three positions of the lever for controllingthe cutter;

FIG. 17 is a simplified flow chart illustrating a method of the presentinvention;

FIGS. 18 and 19 illustrate a method of the present invention;

FIG. 20 schematically illustrates another method of the presentinvention; and

FIG. 21 illustrates a kit of the present invention.

FIG. 22A shows still another device for removing material from a bodylumen.

FIG. 22B shows another view of the device of FIG. 22A

FIG. 23 shows still another device for removing material from a bodylumen.

FIG. 24 shows an end of the device of FIG. 23.

FIG. 25 is an exploded view of FIG. 24.

FIG. 26 shows the device of FIG. 23 with a second opening exposed byrotating the tip of the device.

FIG. 27 is an exploded view of FIG. 26.

FIG. 28 shows a material removal device.

FIG. 29 is a cross-sectional view of the device of FIG. 28.

FIG. 30 shows a syringe used to inject saline through the containmentchamber to remove material therefrom.

FIG. 31 shows a storage container which is used to store the materialremoved from the patient.

FIG. 32 shows the containment chamber inserted into the storagecontainer.

FIG. 33 shows a pin and slot attachment which permits removal of thecontainment chamber.

FIG. 34 show the containment chamber attached to the rest of the deviceand a guidewire positioned in the guidewire lumen to prevent removal ofthe containment chamber.

FIG. 35 shows a pusher element used to push material out of thecontainment chamber.

FIG. 36 shows the pusher element advanced in the containment chamber toforce material out of the first opening.

DETAILED DESCRIPTION OF THE INVENTION

The catheters and methods of the present invention are designed todebulk atheroma and other occlusive material from diseased body lumens,and in particular coronary arteries, de novo lesions, and in-stentrestenosis lesions. The catheters and methods, however, are alsosuitable for treating stenoses of body lumens and other hyperplastic andneoplastic conditions in other body lumens, such as the ureter, thebiliary duct, respiratory passages, the pancreatic duct, the lymphaticduct, and the like. Neoplastic cell growth will often occur as a resultof a tumor surrounding and intruding into a body lumen. Debulking ofsuch material can thus be beneficial to maintain patency of the bodylumen. While the remaining discussion is directed at debulking andpassing through atheromatous or thrombotic occlusive material in acoronary artery, it will be appreciated that the systems and methods ofthe present invention can be used to remove and/or pass through avariety of occlusive, stenotic, or hyperplastic material in a variety ofbody lumens.

Apparatus according to the present invention will generally comprisecatheters having catheter bodies adapted for intraluminal introductionto the target body lumen. The dimensions and other physicalcharacteristics of the catheter bodies will vary significantly dependingon the body lumen which is to be accessed. In the exemplary case ofatherectomy catheters intended for intravascular introduction, theproximal portions of the catheter bodies will typically be very flexibleand suitable for introduction over a guidewire to a target site withinthe vasculature. In particular, catheters can be intended for“over-the-wire” introduction when a guidewire channel extends fullythrough the catheter body or for “rapid exchange” introduction where theguidewire channel extends only through a distal portion of the catheterbody. In other cases, it may be possible to provide a fixed or integralcoil tip or guidewire tip on the distal portion of the catheter or evendispense with the guidewire entirely. For convenience of illustration,guidewires will not be shown in all embodiments, but it should beappreciated that they can be incorporated into any of these embodiments.

Catheter bodies intended for intravascular introduction will typicallyhave a length in the range from 50 cm to 200 cm and an outer diameter inthe range from 1 French to 12 French (0.33 mm: 1 French), usually from 3French to 9 French. In the case of coronary catheters, the length istypically in the range from 125 cm to 200 cm, the diameter is preferablybelow 8 French, more preferably below 7 French, and most preferably inthe range from 2 French to 7 French. Catheter bodies will typically becomposed of an organic polymer which is fabricated by conventionalextrusion techniques. Suitable polymers include polyvinylchloride,polyurethanes, polyesters, polytetrafluoroethylenes (PTFE), siliconerubbers, natural rubbers, and the like. Optionally, the catheter bodymay be reinforced with braid, helical wires, coils, axial filaments, orthe like, in order to increase rotational strength, column strength,toughness, pushability, and the like. Suitable catheter bodies may beformed by extrusion, with one or more channels being provided whendesired. The catheter diameter can be modified by heat expansion andshrinkage using conventional techniques. The resulting catheters willthus be suitable for introduction to the vascular system, often thecoronary arteries, by conventional techniques.

The distal portion of the catheters of the present invention may have awide variety of forms and structures. In many embodiments, a distalportion of the catheter is more rigid than a proximal portion, but inother embodiments the distal portion may be equally as flexible as theproximal portion. One aspect of the present invention provides cathetershaving a distal portion with a reduced rigid length. The reduced rigidlength can allow the catheters to access and treat tortuous vessels andsmall diameter body lumens. In most embodiments a rigid distal portionor housing of the catheter body will have a diameter that generallymatches the proximal portion of the catheter body, however, in otherembodiments, the distal portion may be larger or smaller than theflexible portion of the catheter.

A rigid distal portion of a catheter body can be formed from materialswhich are rigid or which have very low flexibilities, such as metals,hard plastics, composite materials, NiTi, steel with a coating such astitanium nitride, tantalum, ME-92®, diamonds, or the like. Most usually,the distal end of the catheter body will be formed from stainless steelor platinum/iridium. The length of the rigid distal portion may varywidely, typically being in the range from 5 mm to 35 mm, more usuallyfrom 10 mm to 25 mm, and preferably between 6 mm and 8 mm. In contrast,conventional catheters typically have rigid lengths of approximately 16mm.

The side opening windows of the present invention will typically have alength of approximately 2 mm. In other embodiments, however, the sideopening cutting window can be larger or smaller, but should be largeenough to allow the cutter to protrude a predetermined distance that issufficient to debulk material from the body lumen.

The catheters of the present invention can include a flexible atraumaticdistal tip coupled to the rigid distal portion of the catheter. Forexample, an integrated distal tip can increase the safety of thecatheter by eliminating the joint between the distal tip and thecatheter body. The integral tip can provide a smoother inner diameterfor ease of tissue movement into a collection chamber in the tip. Duringmanufacturing, the transition from the housing to the flexible distaltip can be finished with a polymer laminate over the material housing.No weld, crimp, or screw joint is usually required.

The atraumatic distal tip permits advancing the catheter distallythrough the blood vessel or other body lumen while reducing any damagecaused to the body lumen by the catheter. Typically, the distal tip willhave a guidewire channel to permit the catheter to be guided to thetarget lesion over a guidewire. In some exemplary configurations, theatraumatic distal tip comprises a coil. In some configurations thedistal tip has a rounded, blunt distal end. The catheter body can betubular and have a forward-facing circular aperture which communicateswith the atraumatic tip. A collection chamber can be housed within thedistal tip to store material removed from the body lumen. Thecombination of the rigid distal end and the flexible distal tip isapproximately 30 mm.

A rotatable cutter or other tissue debulking assembly may be disposed inthe distal portion of the catheter to sever material which is adjacentto or received within the cutting window. In an exemplary embodiment,the cutter is movably disposed in the distal portion of the catheterbody and movable across a side opening window. A straight or serratedcutting blade or other element can be formed integrally along a distalor proximal edge of the cutting window to assist in severing materialfrom the body lumen. In one particular embodiment, the cutter has adiameter of approximately 1.14 mm. It should be appreciated however,that the diameter of the cutter will depend primarily on the diameter ofthe distal portion of the catheter body.

In exemplary embodiments, activation of an input device can deflect adistal portion of the catheter relative to the proximal portion of thecatheter. Angular deflection of the distal portion may serve one or morepurposes in various embodiments. Generally, for example, deflection ofthe distal portion increases the effective “diameter” of the catheterand causes the debulking assembly to be urged against material in alumen, such as atherosclerotic plaque. In other embodiments, deflectionof the distal portion may act to expose a debulking assembly through awindow for contacting material in a lumen. In some embodiments, forexample, activation of the input device moves the debulking assemblyover a ramp or cam so that a portion of the rigid distal portion andflexible tip are caused to drop out of the path of the debulkingassembly so as to expose the debulking assembly through the window. Insome embodiments, deflection may both urge a portion of the catheterinto material in a lumen and expose a tissue debulking assembly.

Some embodiments further help to urge the debulking assembly intocontact with target tissue by including a proximal portion of thecatheter body having a rigid, shaped or deformable portion. For example,some embodiments include a proximal portion with a bend that urges thedebulking assembly toward a side of the lumen to be debulked. In otherembodiments, one side of the proximal portion is less rigid than theother side. Thus, when tension is placed on the catheter in a proximaldirection (as when pulling the debulking assembly proximally for use),one side of the proximal portion collapses more than the other, causingthe catheter body to bend and the debulking assembly to move toward aside of the lumen to be debulked.

In exemplary embodiments, the debulking assembly comprises a rotatablecutter that is movable outside the window. By moving the cutter outsideof the cutting window beyond an outer diameter of the distal portion ofthe catheter, the cutter is able to contact and sever material that doesnot invaginate the cutting window. In a specific configuration, therotating cutter can be moved over the cam within the rigid, or distal,portion of the catheter body so that the cutting edge is moved out ofthe window. Moving the rotating cutter outside of the cutting window andadvancing the entire catheter body distally, a large amount of occlusivematerial can be removed. Consequently, the amount of material that canbe removed is not limited by the size of the cutting window.

As will be described in detail below, in some situations it ispreferable to provide a serrated cutting edge, while in other situationsit may be preferable to provide a smooth cutting edge. Optionally, thecutting edge of either or both the blades may be hardened, e.g., byapplication of a coating. A preferred coating material is a chromiumbased material, available from ME-92, Inc., which may be appliedaccording to manufacturer's instructions. In some embodiments, thecutter includes a tungsten carbide cutting edge. Other rotatable andaxially movable cutting blades are described in U.S. Pat. Nos.5,674,232; 5,242,460; 5,312,425; 5,431,673; and 4,771,774, the fulldisclosures of which are incorporated herein by reference. In someembodiments, a rotatable cutter includes a beveled edge for removal ofmaterial from a body lumen while preventing injury to the lumen. Instill other embodiments, a tissue debulking assembly may includealternative or additional features for debulking a lumen. For example,the debulking assembly may include, but is not limited to, a radiofrequency device, an abrasion device, a laser cutter and/or the like.

The catheters of the present invention may include a monorail deliverysystem to assist in positioning the cutter at the target site. Forexample, the tip of the catheter can include lumen(s) that are sized toreceive a conventional guidewire (typically 0.014″ diameter) or anyother suitable guidewire (e.g., having diameters between 0.018″ and0.032″) and the flexible proximal portion of the catheter body caninclude a short lumen (e.g., about 12 centimeters in length). Such aconfiguration moves the guidewire out of the rigid portion so as to notinterfere with the debulking assembly.

In other embodiments, however, the guidewire lumen may be disposedwithin or outside the flexible proximal portion of the catheter body andrun a longer or shorter length, and in fact may run the entire length ofthe flexible portion of the catheter body. The guidewire can be disposedwithin lumen on the flexible portion of the catheter body and exit thelumen at a point proximal to the rigid portion of the catheter. Theguidewire can then enter a proximal opening in the tip lumen and exit adistal opening in the tip lumen. In some embodiments, the catheter has adistal guidewire lumen on its flexible distal tip and a proximalguidewire lumen on its flexible body. For example, in some embodimentsthe distal lumen may have a length of between about 2.0 cm and about 3.0cm and the proximal lumen may have a length of between about 10 cm andabout 14 cm. In yet further embodiments, a distal tip guidewire lumenmay be configured to telescope within a proximal guidewire lumen, orvice versa. A telescoping guidewire lumen may enhance performance of thecatheter by preventing a guidewire from being exposed within a bodylumen.

The present invention may optionally employ any of a wide variety ofconventional radiopaque markers, imaging devices, and/or transducers. Inexemplary embodiments, the catheters of the present invention caninclude a radiopaque distal portion and/or radiopaque markers disposedon a distal portion of the catheter body, such as proximal and distal ofthe cutting window, on the cam or ramp, so as to allow the user to trackthe position of the cutter, or the like. The catheters of the presentinvention will also be particularly useful with ultrasonic transducers,such as an IVUS, of a type which may be deployed linearly within thecatheter body or circumferentially on the debulking assembly. Lineardeployment will allow viewing along a discrete length of the catheteraxis, preferably adjacent to the cutting point, usually over a length inthe range from 1 mm to 30 mm, preferably 2 mm to 10 mm.Circumferentially deployed phased arrays may subtend a viewing arc inthe range from 5° to 360°, usually from 180° to 360°. For imagingtransducers located on cutting blades within a housing or second cuttingelement, the field of imaging will generally be limited by thedimensions of the aperture. In some cases, however, it might be possibleto fabricate all or a portion of the cutter blade/housing out of anultrasonically translucent material. A more complete description ofsuitable imaging catheters are described more fully in U.S. patentapplication Ser. No. 09/378,224, filed Aug. 19, 1999, and entitled“Atherectomy Catheter with Aligned Imager,” now U.S. Pat. No. 6,299,622B1, the complete disclosure of which is incorporated herein byreference. In addition to ultrasonic array transducers, the imagingdevices of the present invention may comprise optical coherencetomography devices, such as described in U.S. Pat. No. 5,491,524, thefull disclosure of which is incorporated herein by reference, as well asHuang et al. (1991) Science 254:1178-1181; Brezinski et al. (1997) Heart77:397-403; and Brezinski et al (1996) Circulation 93:1206-1213. In someinstances, the present invention may also provide optical imaging usingoptical wave guides and the like.

Referring now to FIG. 1, a catheter 20 constructed in accordance withprinciples of the present invention comprises a catheter body 22 havinga proximal portion 24 and a distal portion 26. Proximal portion 24 canbe coupled to distal portion 26 with a connection assembly 27 to allowpivoting or deflection of distal portion 26 relative to proximal portion24. A proximal end of the catheter body 22 can have a handle 40 formanipulation by a user, a luer for connection to an aspiration or fluiddelivery channel, or the like.

A debulking assembly, such as a cutter 28, abrasive member, or the like,is disposed within a lumen 30 of the catheter body 22. The cutter 28 istypically rotatable within the distal portion 26 about an axis that isparallel to the longitudinal axis of the distal portion 26 of catheter20 and axially movable along the longitudinal axis. The cutter 28 canaccess target tissue through a side opening window 32 which is typicallylarge enough to allow the cutter 28 to protrude through and move out ofthe window 32 a predetermined distance. The cutter is coupled to acutter driver 34 through a coiled drive shaft 36. Actuation of a movableactuator or other input device 38 can activate the drive shaft 36 andcutter, move cutter 28 longitudinally over a cam so as to deflect thedistal portion and move the cutter 28 out of cutting window 32. Cammingof the cutter 28 can cause the distal portion 26 to pivot or deflectrelative to the proximal portion 24 so as to deflect and urge the cutterinto the tissue in the body lumen.

In some embodiments, the distal portion 26 of the catheter may be movedto an angled or offset configuration from the longitudinal axis of theproximal portion 24 of the catheter and the cutter 28. In someembodiments, the cutter 28 can also be deflected off of the axis of theproximal and/or distal portion of the catheter. Moving the distalportion 26 to an angled/offset position may cause a portion of thecatheter to urge against a target tissue, may expose the cutter 28through the window 32 or both, in various embodiments.

In catheters 20 of the present invention, proximal portion 24 istypically relatively flexible and distal portion 26 is typicallyrelatively rigid. Additionally, many embodiments include a flexibledistal tip 42. The flexible proximal portion 24 of the catheter istypically a torque shaft and the distal portion 26 is typically a rigidtubing. The torque shaft 24 facilitates transportation of the catheterbody 22 and cutter 28 to the diseased site. The proximal end of thetorque shaft 24 is coupled to a proximal handle 40 and the distal end ofthe torque shaft is attached to the distal, rigid portion 26 of thecatheter through the connection assembly 27. The drive shaft 36 ismovably positioned within the torque shaft 24 so as to rotate andaxially move within the torque shaft 24. The drive shaft 36 and torqueshaft 24 are sized to allow relative movement of each shaft withoutinterfering with the movement of the other shaft. The catheter body willhave the pushability and torqueability such that torquing and pushing ofthe proximal end will translate motion to the distal portion 26 of thecatheter body 22.

Referring now to FIG. 1A, a catheter 20 as in FIG. 1 may have a flexibleproximal portion 24 which additionally includes urging means 25. Asshown in FIG. 1A, urging means 25 may comprise a rigid bent or curvedshape towards the distal end of proximal portion 24, which may help urgethe cutter 28 or other debulking apparatus toward a wall of a body lumento enhance treatment. Such a rigid bend increases the working range ofthe catheter by allowing the cutter to be urged into a lumen wall acrossa wider diameter lumen.

In other embodiments, urging means 25 may take many other suitableforms. For example, a similar result to the rigid bend may be achievedby including a rigid distal portion that is not permanently bent butthat is more rigid on one side than on the opposite side of catheterbody 22. Thus, when proximal tension is applied to the proximal portion24, as when proximal force is applied to the debulking apparatus toexpose the cutter 28 through the window 32, the urging means 25 (i.e.,the rigid distal portion of proximal portion 24) will cause the catheterbody 22 to bend toward the less rigid side. The less rigid side willtypically be the same side as the window 32, so that the window 32and/or the cutter 28 will be urged against a wall of a body lumen by thebend. In still other embodiments, a shaped element may be introducedinto catheter body to act as urging means 25. Any suitable urging meansis contemplated.

FIG. 2 illustrates an exploded view of a distal end of the catheter. Insuch embodiments, the catheter 10 includes a connection assembly 27, arigid housing 26, a distal tip 42 that at least partially defines acollection chamber 53 for storing the severed atheromatous material, anda lumen that can receive the guidewire. The distal tip 42 can have adistal opening 43 that is sized to allow an imaging guidewire orconventional guidewire (not shown) to be advanced distally through thetip. In some embodiments, the distal tip 42 may also include a distalguidewire lumen (not shown) for allowing passage of a guidewire. Forexample, some embodiments may include a distal guidewire lumen having alength of between about 1.0 cm and about 5.0 cm, and preferably betweenabout 2.0 cm and about 3.0 cm. Such a distal guidewire lumen may be usedalone or in conjunction with a proximal guidewire lumen located onanother, more proximal, portion of the catheter 20.

In embodiments including a distal guidewire lumen and a proximalguidewire lumen, the distal lumen may be configured to partiallytelescope within a portion of the proximal guidewire lumen, or viceversa. Such telescoping lumens may be used in embodiments where thedistal portion 26 of catheter body 22 is movable relative to theproximal portion 24. A telescoping lumen may enhance performance of thecatheter 20 by allowing a guidewire to be maintained largely within alumen and to not be exposed within the body lumen being treated.Telescoping lumens may have any suitable diameters and configurations toallow for sliding or otherwise fitting of one lumen within another.

A ramp or cam 44 can at least partially fit within the distal portion26. As will be described in detail below, in many embodiments proximalmovement of the cutter 28 over the ramp 44, causes the deflection of thedistal housing 26 and guides cutter 28 out of cutting window 32. (Inother embodiments, a ramp may be used to deflect the distal portionwithout extending the cutter out of the window.) Attached to the ramp 44is a housing adaptor 46 that can connect one or more articulation member48 to the distal tip to create an axis of rotation of the distal portion26. The housing adaptor 46 and articulation member 48 allow the distalend of the catheter to pivot and bias against the body lumen. In theillustrated embodiment there are only one housing adaptor 46 and onearticulation member 48, but it should be appreciated that the cathetersof the present invention can include, two, three, or more joints (e.g.,axis of rotation), if desired. Moreover, the axes of rotation can beparallel or non-parallel with each other.

The catheter can also include a shaft adaptor 50 and collar 52 to couplearticulation member 48 to the torque shaft 22. Shaft adaptor 50 canconnect the housing to the torque shaft and collar 52 can be placed overa proximal end of the shaft adaptor and crimped for a secure attachment.It should be appreciated by one of ordinary skill in the art that thatwhile one exemplary catheter of the present invention has the abovecomponents that other catheters of the present invention may not includemore or fewer of the components described above. For example, somecomponents can be made integral with other components and somecomponents may be left out entirely. Thus, instead of having a separateramp 44, the ramp may be integrated with the distal tip to direct thecutter out of the cutting window.

As shown in FIGS. 3-5, the cutters 28 of the present invention willgenerally be movable between two or more positions. During advancementthrough the body lumen, the cutter will generally be in a neutralposition (FIGS. 3A and 3B) in which the cutter 28 is distal of cuttingwindow 32. In some embodiments, an imaging device (not shown) can becoupled to cutter 28 so as to image the body lumen through cuttingwindow 32 when cutter 28 is in the neutral position. Once the catheter20 has reached the target site, the cutter 28 can be moved to an openposition (FIGS. 4A and 4B) in which the cutter 28 is moved to a proximalend of the cutting window 32 and will extend out of the cutting window32 a distance L₁ beyond an outer diameter D of the rigid portion 26. Inmost embodiments, in the open position, the cutter will have deflectedthe distal portion and the cutter's axis of rotation will generally bein line with connection assembly 27 but angled or offset fromlongitudinal axis of the distal portion of the catheter body.

Optionally, in some embodiments, cutter 28 can be moved to a packingposition, in which the cutter is moved distally, past the neutralposition, so as to pack the severed tissue into a distal collectionchamber 53 (FIGS. 5A and 5B). It should be appreciated however, thatwhile the exemplary embodiment moves the cutter to the above describedpositions, in other embodiments of the present invention the cutter canbe positioned in other relative positions. For example, instead ofhaving the neutral position distal of the cutting window, the neutralposition may be proximal of the window, and the open position may bealong the distal end of the cutting window, or the like.

Referring again to FIGS. 4A and 4B, the interaction of the components ofthe rigid distal portions 26 in one exemplary embodiment of the presentinvention will be further described. As shown in FIG. 4B, the cuttingwindow 32 is typically a cutout opening in the distal portion 26. Whilethe size of the cutting window 32 can vary, the cutting window should belong enough to collect tissue and circumferentially wide enough to allowthe cutter to move out of the cutting window during cutting, but sizedand shaped to not expel emboli into the vasculature. Cams or ramp 44(shown most clearly in FIG. 4B) can be disposed in the distal portion ofthe catheter body to guide or otherwise pivot the cutter 28 out of thecutting window 32 as the cutter 28 is pulled proximally throughtensioning of drive shaft 36.

A joint is located proximal to the cutting window 32 to provide a pivotpoint for camming of the distal portion 26 relative to the proximalportion 24. The bending at a flexible joint 49 is caused by theinteraction of cams or ramps 44 with cutter 28 and the tensile forceprovided through drive shaft 36. In the exemplary configuration, thejoint includes a housing adaptor 46 that is pivotally coupled to thedistal rigid portion 26. As shown in FIGS. 4A and 4B, the resultingpivoting of the rigid distal portion 26 relative to the proximal portioncauses a camming effect which urges the distal housing against the bodylumen wall without the use of urging means (e.g., a balloon) that ispositioned opposite of the cutting window. Thus, the overall crosssectional size of the catheter bodies can be reduced to allow thecatheter to access lesions in smaller body lumens. In exemplaryembodiments, the distal housing can deflect off of the axis of theproximal portion of the catheter typically between 0° degrees and 30°degrees, usually between 5° degrees and 20° degrees, and most preferablybetween 5° degrees and 10° degrees. The angle of deflection relatesdirectly to the urge. Urge, however, does not necessarily relate toforce but more to the overall profile of the catheter. For example, thegreater the angle of deflection, the larger the profile and the biggerthe lumen that can be treated. The ranges were chosen to allow treatmentof vessels ranging from less than 2 mm to greater than 3 mm within thelimits of mechanical design of the components. It should be appreciatedhowever, that the angles of deflection will vary depending on the sizeof the body lumen being treated, the size of the catheter, and the like.

In some embodiments, the deflection of the distal portion 26 of thecatheter urges the cutter into position such that distal advancement ofthe entire catheter body can move the rotating cutter through theocclusive material. Because the cutter is moved a distance L₁ beyond theouter diameter of the distal portion of the catheter and outside of thecutting window, the user does not have to invaginate the tissue into thecutting window. In some embodiments, for example, the cutter can bemoved between about 0.025 mm and about 1.016 mm, and preferably betweenabout 0.025 mm and about 0.64 mm, beyond the outer dimension of thedistal housing. It should be appreciated that the cutter excursiondirectly relates to the depth of cut. The higher the cutter moves out ofthe cutting window the deeper the cut. The ranges are chosen aroundefficacy without risk of perforation of the body lumen.

Some embodiments of the catheter include a shuttle mechanism or othersimilar mechanism for temporarily locking the catheter in a cuttingposition. FIGS. 3C and 3D illustrate such an embodiment in the neutral,non-cutting position. Such embodiments generally include a shuttlemember 45 and a shuttle stop member 42. The shuttle stop member 42 istypically disposed at an angle, relative to a longitudinal axis throughthe catheter. FIGS. 4C and 4D show the same embodiment in the cuttingposition. When the cutter 28 is moved into the cutting position in suchembodiments, the shuttle member 45 falls into the shuttle stop member 42and thus locks the debulking apparatus in a cutting position. To unlockthe debulking apparatus, the cutter 28 may be advanced forward,distally, to release the shuttle member 45 from the shuttle stop member42.

Some embodiments including a shuttle mechanism will also include twojoints in catheter body 22. Thus, catheter body 22 will include aproximal portion 26, a distal portion 24 and a middle portion. Whenshuttle mechanism is activated to expose cutter 28 through window 32,the middle portion may orient itself at an angle, relative to theproximal and distal portions, thus allowing cutter to be urged towards aside of a lumen. Such a two-jointed configuration may provide enhancedperformance of the catheter 20 by providing enhanced contact of thecutter 28 with material to be debulked from a body lumen.

Pushing the entire catheter across a lesion removes all or a portion ofthe lesion from the body lumen. Severed tissue from the lesion iscollected by directing it into a collection chamber 53 in the tip viathe cutter 28. Once the catheter and cutter 28 have moved through thelesion, the cutter 28 can be advanced distally to a “part off position”in which the cutter is moved back into the cutting window 32 (FIG. 3B).The tissue is collected as the severed pieces of tissue are directedinto a collection chamber 53 via the distal movement of cutter 28 andcatheter. The collection chamber 53 of the tip and distal portion 26acts as a receptacle for the severed material, to prevent the severedocclusive material from entering the body lumen and possibly causingdownstream occlusions. The cutter 28 can interact with the distal edgeof the cutting window to part off the tissue and thereafter pack thesevered tissue into collection chamber 53 (FIG. 3B). In exemplaryembodiments, the driver motor can be programmed to stop the rotation ofthe cutter at the part off position so that the cutter 28 can move to athird position (FIG. 5B) and pack the material in the collection chamberin the tip without rotation. Typically, the collection chamber 53 willbe large enough to allow multiple cuts to be collected before the devicehas to be removed from the body lumen. When the collection chamber isfull, or at the user's discretion, the device can be removed, emptiedand reinserted over the guidewire via a monorail system, as will bedescribed below.

In various embodiments, enhancements to the collection chamber 53 may beincluded. For example, in some embodiments the collection chamber 53 maybe configured to be partially or completely translucent or radiolucentand a portion of the catheter surrounding or adjacent to the window 32will be radiopaque. This combination of radiolucent collection chamber53 and radiopaque material adjacent window 32 will enhance the abilityof a user to determine how full the collection chamber 53 is, becausethe fullness of the collection chamber will be directly related to thedistance the cutter 28 can advance forward into the collection chamber53. By facilitating the assessment of collection chamber filling, theseembodiments will reduce the need for manually withdrawing the catheterto examine the collection chamber 53.

In some embodiments, the collection chamber 53 may connect to the rigidhousing by means of interlocking components, which interlock withcomplementary components on the rigid housing. Such components mayresemble a screw-in configuration, for example. Interlocking componentswill provide a stable connection between the collection chamber 53 andthe rigid housing while not increasing the outer diameter of either thechamber 53 or the housing. Generally, collection chamber 53 may be givenany suitable configuration, shape or size. For example, collectionchamber 53 in FIGS. 6-8 has a helical configuration. Alternatively,collection chamber 53 may include a series of circular members, straightlinear members, one solid cylindrical or cone-shaped member or the like.

FIGS. 6 through 8 illustrate one exemplary monorail delivery system toassist in positioning the cutter 28 at the target site. For example, tip42 of the catheter can include a lumen 54 having a distal opening 43 anda proximal opening 55 that is sized to receive a guidewire, having adiameter of about 0.014 in., about 0.018 in., about 0.032 in. or anyother suitable diameter.

As shown in FIG. 8, the flexible proximal portion of the catheter bodymay also include a short lumen 56 (e.g., about 12 centimeters inlength). In some embodiments, however, the guidewire lumen 56 may bedisposed within or outside the flexible proximal portion of the catheterbody and run a longer or shorter length, and in fact may run the entirelength of the flexible portion 24 of the catheter body. In use, theguidewire can be disposed within lumen 56 on the flexible portion of thecatheter body and exit the lumen at a point proximal to the rigidportion 26 of the catheter. The guidewire can then re-enter a proximalopening 55 in the tip lumen 54 and exit through distal opening 43 in thetip lumen. By moving the guidewire outside of the rigid portion 26 ofthe catheter body, the guidewire will be prevented from tangling withthe cutter 28. Typically, tip lumen 54 will be disposed along a bottomsurface of the tip and the lumen 56 will be disposed along a side of theproximal portion 22 of the catheter body so that the guidewire will bein a helical configuration. In various embodiments, the tip lumen 54 andthe proximal lumen 56 can have any suitable combination of lengths. Forexample, in one embodiment the tip lumen 54 may have a length betweenabout 1 cm and about 5 cm, more preferably between about 2 cm and about3 cm, and the proximal lumen may have a length of between about 8 cm andabout 20 cm, more preferably between about 10 cm and about 14 cm.

Referring now to FIGS. 22A and 22B, some catheters 120 of the presentinvention include a proximal guidewire lumen 126 coupled with theproximal portion of the catheter body 123, and a telescoping distalguidewire lumen 124 coupled with either the distal tip 122, part of thedistal portion of the catheter body, or both. The telescoping lumen 124will typically be attached to the tip 122 or a distal portion, but willalso include an unattached portion 121, which will not be directlyattached to any part of the catheter body. This unattached portion 121(or “free floating lumen”) protects a guidewire from contacting a bodylumen in which the device is used and also allows the device to be movedmore freely, without bending or kinking the guidewire. The telescopingguidewire 124 extends within the proximal lumen 126 at the distalopening 127 of proximal lumen 126. Again, the telescoping feature allowsfor movement of the catheter body while preventing or reducing bendingof the guidewire. For example, in some embodiments catheter 120 allowsfor deflection of distal tip 122 and the distal portion of the catheter120 relative to the proximal portion 123, for example by movement abouta pivot point 129. Telescoping distal lumen 124 and proximal lumen 126allow for this movement by allowing distal lumen 124 to telescope withinproximal lumen 126. At the same time, distal lumen 124 protects a guidewire from exposure to a body lumen and/or bodily fluids.

Any suitable configurations and sizes of distal lumen 124 and proximallumen 126 are contemplated. For example, in one embodiment distal lumen124 may telescope within proximal lumen 126 by a distance ofapproximately 1 cm. Furthermore, a telescoping lumen 124 may be longerthan distal lumens in other embodiments. For example, telescoping lumen124 may have a length of between about 2 cm and about 10 cm, andpreferably between about 5 cm and about 8 cm. As is apparent from thedrawing figures, the outer diameter of telescoping distal lumen 124 isconfigured to fit within the inner diameter of proximal lumen 126.Generally, any combination of sizes, lengths, diameters and shapes ofdistal lumen 124 and proximal lumen 126 may be used, to allowtelescoping of one into another.

The catheters of the present invention can include radiopaque markers soas to allow the user to track the position of the catheter underfluoroscopy. For example, as already described, a point or area aroundor adjacent to the window may be made radiopaque. In other embodiments,the rigid distal portion 26 can be radiopaque and radiopaque markers canbe disposed on the flexible shaft. Typically, the markers 59 will bedisposed along the top, proximal to the cutting window, and on thebottom of the catheter to let the user know the position of the cutterand cutting window relative to the target site. If desired, the top andbottom markers can be different shaped so as to inform the user of therelative orientation of the catheter in the body lumen. Because theguidewire will form a helix in its transition from lumen 56 to tip lumen54, the user will be able to view the top and bottom radiopaque markers59 without interference from the guidewire. Some embodiments of thecatheter can also include a radiopaque cutter stop 61 (FIG. 3B) that iscrimped to driveshaft 36 proximal of the cutter that moves with thecutter so as to let the user know when the cutter is in the openposition.

FIGS. 9A through 11D show some exemplary embodiments of the cutter 28 ofthe present invention. The distal portion 60 of the rotatable cutter 28can include a serrated knife edge 62 or a smooth knife edge 64 and acurved or scooped distal surface 66. The distal portion 60 may have anysuitable diameter or height. In some embodiments, for example, thediameter across the distal portion 60 may be between about 0.1 cm andabout 0.2 cm. A proximal portion 68 of the cutter 28 can include achannel 70 that can be coupled to the drive shaft 36 that rotates thecutter. As shown in FIGS. 10A-10C, some embodiments of the cutters caninclude a bulge or bump 69 that is provided to interact with a stent soas to reduce the interaction of the cutting edge with the stent. In anyof the foregoing embodiments, it may be advantageous to construct aserrated knife edge 62, a smooth knife edge 64, or a scooped distalsurface 66 out of tungsten carbide.

Another embodiment of a cutter 28 suitable for use in the presentinvention is shown in side view within a catheter body distal portion 26in FIG. 11D. In this embodiment, the cutter 28 has a beveled edge 64,made of tungsten carbide, stainless steel, titanium or any othersuitable material. The beveled edge 64 is angled inward, toward the axisof rotation (or center) of the cutter 28, creating a “negative angle ofattack” 65 for the cutter 28. Such a negative angle of attack may beadvantageous in many settings, when one or more layers of material aredesired to be debulked from a body lumen without damaging underlyinglayers of tissue. Occlusive material to be removed from a vesseltypically has low compliance and the media of the vessel (ideally to bepreserved) has higher compliance. A cutter 28 having a negative angle ofattack may be employed to efficiently cut through material of lowcompliance, while not cutting through media of high compliance, byallowing the high-compliance to stretch over the beveled surface ofcutter 28.

FIGS. 12 through 16 illustrate an exemplary cutter driver 34 of thepresent invention. As shown in FIGS. 12 and 13, cutter driver 34 can actas the handle for the user to manipulate the catheters 20 of the presentinvention as well as a power source. Typically, the cutter drivers 34 ofthe present invention include a single input device, such as a lever 38that controls the major operations of the catheter (e.g., axial movementto cause urging, rotation to cause cutting, and axial movement forpacking). As shown in FIGS. 13 and 14, cutter driver 34 includes a powersource 72 (e.g., batteries), a motor 74, a microswitch 76 for activatingmotor 74, and a connection assembly (not shown) for connecting the driveshaft 36 to the driver motor 74. In some embodiments, the drive motorcan rotate drive shaft 36 between 1,000 rpm and 10,000 rpm or more, ifdesired.

FIGS. 14 through 16 illustrate one exemplary method of operating cutterdriver 34. In use, the catheter will be delivered to the target sitewith cutter driver unattached and the cutter in the neutral position(FIG. 3B). The cutter driver can be attached with the urge lever 38 in aneutral position (FIG. 14), which indicates that the cutter is closed,but not in a packing position. The user can then move the catheter (andcutter driver unit, if desired) to position the distal portion 26 of thecatheter adjacent the target tissue. As shown in FIG. 15, to activatethe rotation of the cutter, the urge lever 38 can be moved proximallyfrom the neutral position to move the cutter proximally and out ofcutting window 32 (FIG. 4B) and simultaneously depressing microswitch 76to activate motor 74. At the end of the cutting procedure, as shown inFIG. 16, the user can push urge lever 38 completely forward to a distalposition to push the cutter into a packing position (FIG. 5B). After theurge lever passes the middle of the travel, the microswitch 76 can bereleased so as to deactivate the cutter before reaching the packingposition such that packing can occur without the cutter rotating. Itshould be appreciated, while the figures illustrate the use of an urgelever or thumb switch as an input device, the present invention can useother type of input devices, such as labeled buttons (e.g., closewindow, debulk tissue, and pack), or the like.

Advantageously, cutter driver 34 provides an automatic on/off control ofthe cutter 28 that is keyed to the position of the cutter. Such aconfiguration frees the user from the complicated task of rememberingthe sequence of operations to activate and deactivate the rotation andaxial movement of the cutter.

While the cutter driver 34 is illustrated as a disposable batterypowered unit, it should be appreciated that in other embodiments, thecutter driver can use other power sources to control the cutter driver.It should further be appreciated that other cutter drivers can be usedwith the present invention. While not preferred, it is possible to haveseparate controls to control the axial movement of the cutter and therotation of the cutter.

Some exemplary methods of the present invention will now be described.One method of the present invention comprises delivering a catheter to atarget site in the body lumen. A distal portion of the catheter can bedeflected relative to a proximal portion of the catheter to expose atissue debulking device in the catheter. The body lumen can be debulkedwith the exposed debulking device. Specifically, as shown schematicallyin FIG. 17, one specific method comprises advancing a catheter to atarget site (Step 100). A cutter can be rotated and moved out of thecutting window (Steps 102, 104). Preferably, a distal portion of thecatheter can be pivoted or deflected so as to position the cutteradjacent the target material. Thereafter, the catheter and the rotatingcutter can be moved through the body lumen to remove the target materialfrom the body lumen (Step 106).

As shown in FIGS. 18 and 19, the catheter can be percutaneously advancedthrough a guide catheter or sheath and over a conventional or imagingguidewire using conventional interventional techniques. The debulkingcatheter 20 can be advanced over the guidewire and out of the guidecatheter to the diseased area. As shown in FIG. 18, the window 32 willtypically be closed (with the cutter or other debulking device 28 in afirst, distal position). As shown in FIG. 19, catheter 20 will typicallyhave at least one hinge or pivot connection to allow pivoting about oneor more axes of rotation to enhance the delivery of the catheter intothe tortuous anatomy without dislodging the guide catheter or othersheath. The cutter can be positioned proximal of the lesion. Optionally,a transducer, IVUS, or other imaging assembly can be used to verify theposition of the debulking catheter.

Once the position of the catheter is confirmed, the cutter 28 will beretracted proximally and moved out of cutting window 32 to its second,exposed position. In some embodiments, movement of the cutter candeflect the distal portion of the catheter to increase the profile ofthe catheter at the target site. Movement of the cutter is typicallycaused by proximal movement of lever 38 and tensioning of drive shaft36. Movement of the lever can be scaled to any desired ratio or a direct1:1 ratio of movement between the handle and cutter. When the cutter ismoved proximally it contacts ramp or cam surfaces so as to guide thecutter up and at least partially out of the cutting window 32.Additionally, as shown by arrow 80, the distal portion of catheter body26 rotates about the joint 49 to provide an urging force for the cutter(and catheter body) to move toward the diseased area.

Thereafter, as shown by arrow 82 the operator can move the entirecatheter body 22 through the lesion to dissect the tissue. As the cutter28 and catheter body 22 are advanced distally through the lesion, tissuethat is trapped between the cutting edge 52 and the cutting window 32 issevered from the body lumen. To part off the tissue, the operator canstop pushing the device distally and the cutter can be advanced distallyinside the cutting window by advancing the handle 38. During the distalmovement of the cutter, the cutter 28 rides back over the ramps 44 anddirects the cutter back inside of the cutting window 32. Such movementcauses the distal portion 26 of the catheter to move in line with thecutter and proximal portion 24 (FIG. 5B). When the cutter has moved toits distal position, the cutter parts off the severed tissue and urgesthe severed tissue inside of a collection chamber 53 in the distal tip42. Optionally, after the cutter 28 has parted off the tissue, the lever38 and thus the non-rotating cutter 38 can be advanced distally to packthe tissue into the collection chamber 53 (FIG. 5B). Use of the cutterto pack the severed tissue will allow the operator multiple specimens tobe collected prior to removing the catheter 20 from the body lumen. Whenit is determined that the collection chamber is full, the catheter canbe removed from the body lumen and the collection chamber can beemptied.

In another method of the present invention, as shown in FIG. 20, aninput device is disposed in a first position to position a tissueremoval element in a neutral position (Step 120). The input device isactivated to rotate the tissue removal element and to axially move thetissue removal device to an active position (Step 122). The input devicecan then be activated again to move the tissue removal element to apacking position (Step 124). In an exemplary embodiment, the inputdevice is a lever or thumb switch that can be moved to correspond to themovement of a cutting element on the catheter. Thus, as the lever ismoved proximally, the cutter is rotated and moved proximally to an openposition. When the lever is moved to a distal position, the rotation ofthe cutter can be stopped and the cutter can be moved distally to packsevered tissue into a collection chamber.

Referring now to FIG. 21, the present invention will further comprisekits including catheters 200, instructions for use 202, and packages204. Catheters 200 will generally be as described above, and theinstruction for use (IFU) 202 will set forth any of the methodsdescribed above. Package 204 may be any conventional medical devicepackaging, including pouches, trays, boxes, tubes, or the like. Theinstructions for use 202 will usually be printed on a separate piece ofpaper, but may also be printed in whole or in part on a portion of thepackaging 204.

Referring to FIG. 23, another atherectomy device 200 is shown. Althoughthe atheterectomy device 200 may take on many different configurations,the atherectomy device 200 does have particular advantages over otherdevices as described herein and in applications and patents incorporatedby reference. The catheter 200 may be constructed in any suitable mannerincluding those methods described herein and in the patents andapplications incorporated by reference.

The atherectomy device 200 has a rotating cutting element 202 which canmove between the stored and working positions with a portion of thecutting element 202 becoming exposed through a first opening 204 whenmoving to the working position of FIG. 23. The device 200 is advancedthrough the blood vessel with the cutting element 202 in the workingposition so that material severed by the cutting element is directedthrough the first opening 204 and into a containment chamber 206. Thedevice 200 is advanced over a guidewire 208 which extends through aguidewire lumen 210 on the device 200.

A distal portion 212 or tip of the device 200 may articulate or bendwhen the cutting element 202 moves from the stored position to theworking position as described above and in the patents and applicationsincorporated by reference. Articulation or bending of the distal portion212 tends to move the first opening 204 toward the wall of the bloodvessel. The tip 212 may articulate in any suitable manner and variousaspects of the present invention may be practiced with other featuresfor moving the first opening 204 toward the wall of the blood vessel andorienting the cutting element 202 in an advantageous position withoutdeparting from the present invention.

The material cut by the cutting element 202 is directed through thefirst opening 204 and into a containment chamber 216 located distal tothe first opening 204. The device 200 may be passed through the vessel anumber of times with the material from each pass being stored in thecontainment chamber 216. When the containment chamber 216 is full, thedevice 200 is removed from the patient and the collection chamber 216may be cleaned for subsequent use as described below.

Referring now to FIGS. 23-27, a second opening 218 may be created in thedevice 200 to help remove the material stored in the containment chamber216. The device 200 may have a movable section 220 which is moved toexpose or otherwise create the second opening 218. The movable portion220 pivots or rotates to move between the closed position of FIG. 24 andopen position of FIG. 26. For clarity, FIGS. 25 and 27 show the movablesection 220 separated from the rest of the device 200 when oriented inthe open and closed positions.

The movable section 220 may be located at the distal end of thecontainment chamber 216 near the distal tip of the device 200 oppositethe first opening 204 although other locations may be used. The movablesection 220 may have a curved section 222 which forms a ramp 224 todirect material out of the second opening 218 when in open position ofFIG. 26. The bottom portion of the ramp 224 covers the second opening218 when rotated into the closed position of FIG. 24. Of course, thesecond opening 218 may be created in any other manner without departingfrom various aspects of the present invention.

The guidewire lumen 210 extends along the device with a section 230 ofthe guidewire lumen 208 mounted to the movable section 220. In thismanner, the movable section 220 may be locked by the guidewire 208. Theguidewire 208 may lock the movable section 220 in another suitable wayto prevent creation of the second opening 218 such as a biased lockingelement held in place by the guidewire 208 when resident in theguidewire lumen 210. When the device 200 is removed from the patient,the guidewire 208 is removed from the guidewire lumen 210 which permitsrotation of the movable section to open the second opening 218.

Removal of the material from the containment chamber 216 is nowdescribed. The device 200 is removed from the patient and the guidewire208 is removed from at least the section 230 of the guidewire lumen 210along the movable section 220. The movable section 220 is then rotatedto create the second opening 218.

Referring to FIGS. 28-30, the containment chamber 216 may then bemounted to a material removal device 236. The material removal device236 has a throughhole 238 which forms a cavity 240 that receives thecontainment chamber 216. The device 200 has a first seal 242 and asecond seal which both form a circumferential seal around the shaft onboth sides of the first opening 204 to isolate the first opening 204from the second opening 218 except through the containment chamber 216.A fluid, either liquid or gas and preferably saline, is then deliveredthrough the first opening 204 to force the material out of the secondopening 218. The fluid may be delivered in any suitable manner such aswith a syringe 220 or pump. The material removal device 236 may alsoform a seal around the second opening 218. For example, the containmentchamber 216 may be introduced into a storage container 244 which has aseal 246 which isolates the second opening 218 as well. Although thefirst and second seals 242, 246 are shown as being independent they mayalso be formed by the same structure.

Once the second opening 218 has been created, material in thecontainment chamber 216 may be removed in a number of different ways.Referring to FIGS. 35 and 36, for example, a separate pusher 250 may beadvanced into the containment chamber 216 to force material out of oneof the openings 204, 218. The various methods may be combined, ofcourse, to clear material from the containment chamber 216. For example,the cutting element 202 or a pusher element 250 (see FIGS. 35 and 36)may be used before, during or after use of the fluid to move thematerial from the containment chamber 216.

The material may simply be discarded in the appropriate manner afterremoval from the device. Alternatively, the material may also be savedin the storage container 244. The storage container 244 receives thematerial and a portion of the fluid used to flush the material from thecontainment chamber 216. The storage container 244 is then sealed topreserve the material for subsequent analysis as described in theapplications incorporated by reference herein. Referring to FIGS. 31 and32, the storage container 244 may include a valve or seal 252, such as aslit or duckbill valve, which permits introduction of part of thecontainment chamber 216 and seals the container 244 when the device isremoved. The material in the container 244 may then be examined for anypurpose such as to determine whether additional treatment is warranted.

The material may be stored in the container 244 using the fluid used toflush the material from the chamber 216. As shown in FIG. 32, thecontainment chamber 216 itself is used to open the seal by inserting thedevice through the seal 252. The material may be delivered directly intothe storage container 244 from the device or may be delivered through alumen, tube, intermediate chamber or the like on the material removaldevice or other device.

Referring now to FIGS. 23, 33 and 34, the device 200 may be designed sothat the containment chamber 262 is removable. In particular, thepresent invention contemplates a system or kit including two or moreremovable containment chambers 216. One advantage of such a system isthat the procedure time may be decreased compared to a device havingonly one containment chamber which must be cleaned before reintroducingthe device into the patient. Depending upon the particular application,the containment chamber 262 might be filled and emptied a number oftimes. This requires the chamber 262 to be cleaned before being mountedagain to the device for introduction into the patient. By providing tworemovable containment chambers 262 the user may remove the firstcontainment chamber 262 when it is desired to remove the materialcontained therein and replace the first containment chamber 262 with theempty second containment chamber 262 and then reintroduce the device200. The first containment chamber 262 may then be emptied while theuser continues to remove material using the second containment chamber262. For example, the pusher element 250 may be used to push materialout of the chamber 262 (see FIGS. 35 and 36).

The containment chamber 262 has an interlocking pin 264 and slot 266connection although any other suitable mechanism may be used. The pin264 is advanced into the slot 266 and the containment chamber 262 isthen rotated to align a section 268 of the guidewire lumen mounted tothe containment chamber 262 with the rest of the guidewire lumen. Theguidewire then acts to lock the containment chamber 262 and preventdetachment within the patient similar to other devices described herein.

Referring now to FIGS. 35 and 36, another atherectomy device 280 isshown which operates in essentially the same manner as the devicesdescribed above. The device 280 has a second opening 282 which iscreated by expanding or dilating a portion of the body. The secondopening 282 may have any suitable structure which can be expanded suchas a slit valve or duck bill valve. The second opening 282 is opened andthe material is then removed by forcing the material out of one of theopenings. The material may be forced through the second opening usingthe pusher element 250, a fluid in the manner described above, thecutting element 202 or any combination thereof. FIGS. 35 and 36 showsthe pusher element 250 forcing material through the first opening 204,however, the pusher 250 may also be used to push material out of thesecond opening when introduced through the first opening 204 or throughthe exposed open end created when the containment chamber is removed asdescribed above.

Referring to FIG. 23, another atherectomy device 200 is shown. Althoughthe atherectomy device 200 may take on many different configurations,the atherectomy device 200 does have particular advantages over otherdevices as described herein and in applications and patents incorporatedby reference. The catheter 200 may be constructed in any suitable mannerincluding those methods described herein and in the patents andapplications incorporated by reference.

The atherectomy device 200 has a rotating cutting element 202 which canmove between the stored and working positions with a portion of thecutting element 202 becoming exposed through a first opening 204 whenmoving to the working position of FIG. 23. The device 200 is advancedthrough the blood vessel with the cutting element 202 in the workingposition so that material severed by the cutting element is directedthrough the first opening 204 and into a containment chamber 206. Thedevice 200 is advanced over a guidewire 208 which extends through aguidewire lumen 210 on the device 200.

A distal portion 212 or tip of the device 200 may articulate or bendwhen the cutting element 202 moves from the stored position to theworking position as described above and in the patents and applicationsincorporated by reference. Articulation or bending of the distal portion212 tends to move the first opening 204 toward the wall of the bloodvessel. The tip 212 may articulate in any suitable manner and variousaspects of the present invention may be practiced with other featuresfor moving the first opening 204 toward the wall of the blood vessel andorienting the cutting element 202 in an advantageous position withoutdeparting from the present invention.

The material cut by the cutting element 202 is directed through thefirst opening 204 and into a containment chamber 216 located distal tothe first opening 204. The device 200 may be passed through the vessel anumber of times with the material from each pass being stored in thecontainment chamber 216. As will be described below, material in thecontainment chamber 16 may be removed as desired and the devicereintroduced a number of times to remove more material at the same ordifferent locations.

Referring now to FIGS. 23-27, a second opening 218 may be created in thedevice 200 to help remove the material stored in the containment chamber216. The device 200 may have a movable section 220 which is moved toexpose or otherwise create the second opening 218. The movable portion220 pivots or rotates to move between the closed position of FIG. 24 andopen position of FIG. 26. For clarity, FIGS. 25 and 27 show the movablesection 220 separated from the rest of the device 200 when oriented inthe open and closed positions.

The movable section 220 may be located at the distal end of thecontainment chamber 216 near the distal tip of the device 200 oppositethe first opening 204 although other locations may be used. The movablesection 220 may have a curved section 222 which forms a ramp 224 todirect material out of the second opening 218 when in open position ofFIG. 26. The bottom portion of the ramp 224 covers the second opening218 when rotated into the closed position of FIG. 24. Of course, thesecond opening 218 may be created in any other manner without departingfrom various aspects of the present invention.

The guidewire lumen 210 extends along the device with a section 230 ofthe guidewire lumen 208 mounted to the movable section 220. In thismanner, the movable section 220 may be locked by the guidewire 208. Theguidewire 208 may lock the movable section 220 in another suitable wayto prevent creation of the second opening 218 such as a locking elementbiased by the guidewire 208 when positioned in the guidewire lumen 210.When the device 200 is removed from the patient, the guidewire 208 isremoved from the guidewire lumen 210 which permits rotation of themovable section to open the second opening 218.

Removal of the material from the containment chamber 216 is nowdescribed. The device 200 is removed from the patient and the guidewire208 is removed from at least the section 230 of the guidewire lumen 210.The movable section 220 is then rotated to create the second opening218.

Referring to FIGS. 28-30, the containment chamber 216 may then bemounted to a material removal device 236 which may include a storagecontainer 244 to form a system or kit for removing material. Thematerial removal device 236 has a throughhole 238 which forms a cavity240 that receives the containment chamber 216. The device 200 has afirst seal 242 and a second seal 243 which forms circumferential sealson both sides of the first opening 204 to isolate the first opening 204from the second opening 218 except through the containment chamber 216.A fluid, either a gas or a liquid such as saline, is then deliveredthrough the first opening 204 to force the material out of the secondopening 218. The fluid may be delivered in any suitable manner such aswith a syringe 220 or pump. The material removal device 236 may alsoform a seal around the second opening 218. For example, the containmentchamber 216 may be introduced into a storage container 244 which has aseal 246 which isolates the second opening 218 as well. Although thefirst and second seals 242, 246 are shown as being independent they mayalso be formed by the same structure.

Once the second opening 218 has been created, material in thecontainment chamber 216 may be removed in a number of different ways.Referring to FIGS. 35 and 36, for example, a separate pusher 250 may beadvanced into the containment chamber 216 to force material out of oneof the openings 204, 218. The various methods may be combined, ofcourse, to clear material from the containment chamber 216. For example,the cutting element 202 or a pusher element 250 (see FIGS. 35 and 36)may be used before, during or after use of the fluid to move thematerial from the containment chamber 216.

The material may simply be discarded in the appropriate manner afterremoval from the device. Alternatively, the material may also be savedin the storage container 244. The storage container 244 receives thematerial and a portion of the fluid used to flush the material from thecontainment chamber 216. The storage container 244 is then sealed topreserve the material for subsequent analysis as described in theapplications incorporated by reference herein. Referring to FIGS. 31 and32, the storage container 244 may include a valve or seal 252, such as aslit or duckbill valve, which permits introduction of part of thecontainment chamber 216 and seals the container 244 when the device isremoved. The material in the container 244 may then be examined for anypurpose such as to determine whether additional treatment is warranted.

The material may be stored in the container 244 using the fluid used toflush the material from the chamber 216. As shown in FIG. 32, thecontainment chamber 216 itself is used to open the seal 252 by insertingthe device through the seal 252. The material may be delivered directlyinto the storage container 244 from the device or may be deliveredthrough a lumen, tube, intermediate chamber or the like on the materialremoval device or other device.

Referring now to FIGS. 23, 31 and 32, the device 200 may be designed sothat the containment chamber 262 is removable. In particular, thepresent invention contemplates a system or kit including two or moreremovable containment chambers 216. One advantage of such a system isthat the procedure time may be decreased compared to a device havingonly one containment chamber which must be cleaned before beingreintroduced into the patient. Depending upon the particularapplication, the containment chamber 262 might be filled five or moretimes. By providing two removable containment chambers 262 the user mayreplace a containment chamber 262 containing material with an emptycontainment chamber 262 and then reintroduce the device 200. The firstcontainment chamber 262 may then be emptied by another person while theuser continues to remove material which will now be held in the secondcontainment chamber 262. For example, the pusher element 264 may be usedto push material out of the chamber 262 from the second end out of theopen end of the containment chamber 262

The containment chamber 262 has an interlocking pin 264 and slot 266connection although any other suitable mechanism may be used. The pin264 is advanced into the slot 266 and the containment chamber 262 isthen rotated to align a section 268 of the guidewire lumen mounted tothe containment chamber 262 with the rest of the guidewire lumen. Theguidewire then acts to lock the containment chamber 262 and preventdetachment within the patient similar to other devices described herein.

Referring now to FIGS. 35 and 36, another atherectomy device 280 isshown which operates in essentially the same manner as the devicesdescribed above. The device 280 has a second opening 282 which iscreated by expanding or dilating a portion of the body. The secondopening 282 may have any suitable structure which can be expanded suchas a slit valve or duck bill valve. The second opening 282 is opened andthe material is then removed by forcing the material out of one of theopenings. The material may be forced through the second opening 282using the pusher element 250, a fluid in the manner described above, thecutting element 202 which would push the material out of the secondopening 282 or any combination thereof. FIGS. 35 and 36 shows the pusherelement 250 forcing material through the first opening 250 but thepusher 250 may also be used to push material out of the second openingwhen introduced through the first opening 204 or through the exposedopen end created when the containment chamber is removed as describedabove.

While all the above is a complete description of the preferredembodiments of the inventions, various alternatives, modifications, andequivalents may be used. For example, while preferred cutters are movedproximally to move the cutter out of the cutting window, alternativeembodiments may move the cutter distally to move the cutter out of thecutting window. Additionally, while most embodiments employ a cutterthat extends out beyond the outer diameter of the cutting window, it maybe possible to incorporate a cutter that stays within the diametercatheter body. Additionally, in some embodiments, the debulking assemblymay be exposed through the window without causing a deflection of thedistal portion of the catheter. Moreover, instead of having a distal tipthat is rotatable relative to the proximal portion of the catheter, thecatheter can include a shape memory material such that the catheterforms a jog or a pre-bent shape when it reaches its target area.Although the foregoing invention has been described in detail forpurposes of clarity of understanding, it will be obvious that certainmodifications may be practiced within the scope of the appended claims.

1. An atherectomy device for removing material from a vascular locationcomprising: an elongate body having proximal and distal ends and a firstinterlocking member; a torque transmitting element contained within theelongate body, the torque transmitting element being rotatable; anopening in the elongate body proximal to the distal end of the elongatebody; a cutting element coupled to the torque transmitting element, thecutting element being rotated by the torque transmitting element whencutting material from the vascular location, the cutting element beingoriented to direct the material being cut from the vascular locationthrough the opening; and a containment chamber having proximal anddistal ends and a second interlocking member, the first interlockingmember being configured to engage with the second interlocking member,the first interlocking member being movable with respect to the secondinterlocking member from an unlocked position where the containmentchamber is not attached to the elongate body to a locked position wherethe containment chamber is attached to the elongate body, thecontainment chamber being configured for receiving the material passingthrough the opening which has been cut by the cutting element.
 2. Theatherectomy device of claim 1 wherein the first interlocking member ispositioned adjacent the distal end of the elongate body.
 3. Theatherectomy device of claim 1 wherein the second interlocking member ispositioned adjacent the proximal end of the containment chamber.
 4. Theatherectomy device of claim 1 wherein the first interlocking member is apin extending from the elongate body.
 5. The atherectomy device of claim1 wherein the second interlocking member is a slot formed in a wall ofthe containment chamber.
 6. The atherectomy device of claim 1 whereinthe elongate body has a first guidewire lumen and the containmentchamber has a second guidewire lumen, the first and second guidewirelumens being axially aligned when the first and second interlockingmembers are in the locked position.
 7. The atherectomy device of claim 6wherein the first and second interlocking members are configured to befixed in the locked position when a guidewire is received within thefirst and second guidewire lumens.
 8. A method of removing material froma target site in a body lumen using an atherectomy device, comprising:providing an atherectomy device having an elongate body with an openingproximal of a distal end of the elongate body, a cutting element, and afirst containment chamber, the first containment chamber being removablyattached to the elongate body; advancing the atherectomy device throughthe body lumen to the target site; cutting material from the body lumenat the target site using the cutting element, the material being cut bythe cutting element passing through the opening and into the firstcontainment chamber; withdrawing the atherectomy device from the bodylumen; and after the atherectomy device has been withdrawn from the bodylumen detaching the first containment chamber from the elongate body. 9.The method of claim 8 further comprising: providing a second containmentchamber; attaching the second containment chamber to the elongate bodyafter the first containment chamber has been detached from the elongatebody; advancing the atherectomy device with the second containmentchamber through the body lumen to the target site; and cutting materialfrom the body lumen at the target site using the cutting element, thematerial being cut by the cutting element passing through the openingand into the second containment chamber.
 10. The method of claim 8,further comprising the step of: changing the position of the cuttingelement so that part of the cutting element is exposed through the firstopening during the cutting step.
 11. The method of claim 9 wherein theelongate body has a first interlocking member and the first and secondcontainment chambers each have a second interlocking member, the firstinterlocking member being configured to engage with the secondinterlocking member of one of the first and second containment chambers,the first interlocking member being movable with respect to the secondinterlocking member from an unlocked position where the containmentchamber is not attached to the elongate body to a locked position wherethe containment chamber is attached to the elongate body.
 12. The methodof claim 9 wherein the first interlocking member is positioned adjacentthe distal end of the elongate body.
 13. The method of claim 9 whereinthe second interlocking member of each of the first and secondcontainment chambers is positioned adjacent the proximal end of thecontainment chamber.
 14. The method of claim 9 wherein the firstinterlocking member is a pin extending from the elongate body.
 15. Themethod of claim 9 wherein the second interlocking member of each of thefirst and second containment chambers is a slot formed in a wall of thecontainment chamber.
 16. The method of claim 11 wherein the elongatebody has a first guidewire lumen and wherein each of the first andsecond containment chambers have a second guidewire lumen, the firstguidewire lumen being axially aligned with the second guidewire lumen ofone of the first and second containment chambers when the firstinterlocking member and second interlocking member of one of the firstand second containment chambers are in the locked position.
 17. Themethod of claim 11 wherein the first interlocking member and secondinterlocking member of one of the first and second containment chambersare configured to be fixed in the locked position when a guidewire isreceived within the first guidewire lumen and second guidewire lumen ofone of the first and second containment chambers.
 18. An atherectomy kitfor removing material from a vascular lumen comprising: a catheterhaving an elongate body with proximal and distal ends and an opening,and a cutting element positioned to direct the material being cut fromthe vascular location through the opening; first and second containmentchambers, each containment chamber having proximal and distal ends andbeing configured to be removably connected to the elongate body of thecatheter, such that during use of the catheter in the body lumen theelongate body of the catheter is configured to be attached,alternatively, to one of the first and second containment chambers, thefirst containment chamber being configured for receiving the materialpassing through the opening in the elongate body of the catheter whenattached during use of the catheter in the body lumen, the secondcontainment chamber being configured for receiving the material passingthrough the opening in the elongate body of the catheter when attachedduring use of the catheter in the body lumen; instructions describingthe method of using the kit to remove material from the vascular lumen;and a package configured to contain the catheter, first and secondcontainment chambers and the instructions.
 19. The kit of claim 18wherein the elongate body has a first interlocking member and the firstand second containment chambers each have a second interlocking member,the first interlocking member being configured to engage with the secondinterlocking member of one of the first and second containment chambers,the first interlocking member being movable with respect to the secondinterlocking member from an unlocked position where the containmentchamber is not attached to the elongate body to a locked position wherethe containment chamber is attached to the elongate body.
 20. The kit ofclaim 19 wherein the first interlocking member is positioned adjacentthe distal end of the elongate body.
 21. The kit of claim 19 wherein thesecond interlocking member of each of the first and second containmentchambers is positioned adjacent the proximal end of the containmentchamber.
 22. The kit of claim 19 wherein the first interlocking memberis a pin extending from the elongate body.
 23. The kit of claim 19wherein the second interlocking member of each of the first and secondcontainment chambers is a slot formed in a wall of the containmentchamber.
 24. The kit of claim 19 wherein the elongate body has a firstguidewire lumen and wherein each of the first and second containmentchambers have a second guidewire lumen, the first guidewire lumen beingaxially aligned with the second guidewire lumen of one of the first andsecond containment chambers when the first interlocking member andsecond interlocking member of one of the first and second containmentchambers are in the locked position.
 25. The kit of claim 19 wherein thefirst interlocking member and second interlocking member of one of thefirst and second containment chambers are configured to be fixed in thelocked position when a guidewire is received within the first guidewirelumen and second guidewire lumen of one of the first and secondcontainment chambers.